Blackberries
Would be like finding a gold mine, a delicious gold mine.
That will dominate your yard and yield within reach only bitter, unripe berries without extracting a pint of blood for each morsel.
That looks like wild groundcover strawberries, or something very similar.
Definitely not poison oak.
Leaves of 3 let me be
If I'm hairy, I'm a berry
Poison oak vines are absolutely hairy when the plant is of sufficient size. It’s all over NC - god knows I see it enough.
You didn't say where you live. Assuming its Calif, then my guess is stinging nettle, if it has sharp little hairs. If it doesn't, scrunch some up and tell us if its fragrant. (but the more I look at it, the more I think its the nettle). Be careful, you'll get a rash from that shit, but nothing as bad as poison oak, more temporary.
https://www.google.com/search?q=sti...jAhWcJDQIHX7MBosQ_h0wFXoECAoQBw#imgrc=_&vet=1